Corrugated paper board product



July 2, 1963 s. GOLDSTEIN ETAL 3,096,224

CORRUGATED PAPER BOARD PRODUCT Original Filed Oct. 2, 1953 2 Sheets-Sheet 1 'i a; w iaa/iP/ in 1+ "3 $4 5 'if r iZ'.

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SAMUEL GOLDSTE/N (DECEASED) av MANUFACTURERS HANOVER TRUST COMPANZ (EXECUTOIZ) IMMANUEL LICHTENSTE/N y 1963 s. GOLDSTEIN ETAL 3,

CORRUGATED PAPER BOARD PRODUCT Original Filed Oct. 2, 1953 2 Sheets-Sheet 2 Tia. '5.

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--- SAMUEL G'OLDSTEIN (DECEASED) 3v MANUFACTURERS HANOVER TRUST COMPANY, (EXECUTO IM MANUEL L/CHTENSTE/N ATTUQA/EVJ United States Patent 3,096,224 CORRUGATED PAPER BOARD PRODUCT Samuel Goldstein, deceased, late of New York, N.Y., by Manufacturers Hanover Trust Company, executor, Sew York, N.Y., and Immanuel Lichtenstein, Cambridge, Mass., assignors to Tri-Wall Containers, Inc., New York, N .Y., a corporation of New York Continuation of application Ser. No. 604,429, Aug. 16, 1956, which is a division of application Ser. No. 383,756, Oct. 2, 1953, now Patent No. 2,759,523, dated Aug. 21, 1956. This application Nov. 3, 1961, Ser.

3 Claims.

This invention relates to corrugated paper board products.

Corrugated paper board has many uses, the major one of which is the making of cartons for shipping a large variety of products. Such cartons most commonly have been made of double face single wall or ply corrugated paper board. Cartons are also made of double ply corrugated paper board, a structure which combines two cor-a rugated sheets interposed between three spaced liner sheets.

While attempts had been made to produce triple ply corrugated paper board in which three corrugated sheets are interposed between four spaced liner sheets, insofar as the present inventors were aware, such a composite sheet of corrugated paper board had not been successfully produced commercially to any great extent.

Triple wall corrugated paper board has many distinct advantages, particularly in packaging relatively heavy objects, and also in protecting relatively trail objects in transit. It is rigid and strong, comparing favorably in strength with wood as a packaging medium, cost considered, and in addition has a cushioning quality which cannot be approached by wood.

Implicitly in the above is the object of this invention, namely, to provide corrugated paper board that is stronger than double wall corrugated paper board, to a degree permitting its use instead of wood as a packaging material for shipping objects too heavy to be shipped in prior art corrugated paper board containers.

This application is a continuation of application Serial No. 604,429, field August 16, 1956, now abandoned, which was a division of original application Serial No. 383,756, filed October 2, 1953, on which Patent 2,759,- 523 issued August 21, 1956.

In the following disclosure of this invention, the original application is relied on for priority as to all essential parts. As in the original application, only one mode of operation of the necessary corrugated paper board machine is described. This is the best mode contemplated by the inventors, as will become apparent from the following.

Having reference to the accompanying drawings:

FIG. 1 is a diagrammatic longitudinal view of the combining, scoring and cut off end of a corrugated paper board machine in which the novel features of our invention have been incorporated to enable the production of triple wall corrugated paper board of the present invention; 1

FIG. 2 is a top plan view of FIG. 1;

FIG. 3 is a plan view of a composite corrugated board sheet scored by the scoring device disclosed herein, parts being broken away to show the direction in which the corrugations extend; I

FIG. 4 is a sectional view taken substantially on the line 4-4 of FIG. 3;

FIG. 5 is a vertical sectional view of a duplex scoring machine in which the scoring devices used to score the product have been incorporated; and,

FIG. 6 is an enlarged sectional view of the rotatable scoring dies.

In FIG. 1, the present inventors show the combining end of a corrugated paper board machine. Concerning the parts of the corrugated paper board machine (not shown), it should be sufiicient to state that the sheets of paper are corrugated transversely of the direction of travel through the machine and adhesively applied to liner sheets all in a manner well-known in the art to which this invention relates.

In steps previous to those shown in FIG. 1, three sheets, 11, 12 and 13 are corrugated and the ridges of the corrugations adhesively secured to liner sheets 14, 16 and 17 thus forming three composite sheets of single face corrugated paper board.

The three sheets of single face corrugated paper board are brought into juxtaposition, at the end of the bridge adjacent to the end of the machine shown by FIG. 1, and brought over guides 18 and pass over hot preheater drums 19. These preheater drums are supplied with high temperature steam by means not shown, but well understood in the art. The preheater drums 19 may be supported by a frame 21 which also serves as a support for arms 22 which carry idler rollers 23. The frame 21 may be supported in any suitable manner as indicated at 24 from the main part of the machine generally indicated by the numeral 26. An outer liner 27 from a mill roll mounted on the first of the mill roll supports 10c, passes around an idling roller 28 and around a preheating drum 29 and thence around a idling roller 31. The three sheets of single face corrugated paper board and the liner sheet 27 thus preheated are brought to gluing rolls 32 where glue is applied to the ridges of the corrugations which extend transversely of the direction of the travel of the webs of paper and the four juxtaposed webs of paper are brought together beneath a belt 33. The belt 33 may be of canvas or any other suitable material and is mounted on pulleys 34, one of which constitutes a driving pulley driven by means not shown.

One of the problems encountered in making triple wall corrugated paper board is that the sheets are relatively heavily laden with moisture as they leave the portions of the machine to the left of the combining end of the machine shown in FIG. 1. This may be one of the major reasons no method of making triple corrugated paper board was successful commercially prior to the present invention.

It will be appreciated that large quantities of steam are employed in forming the corrugations, steam jets being applied to the paper to condition it for corrugating. The air of the building which the machine occupies is heavily laden with moisture which is absorbed by the liner sheets as the webs travel through the machine to the combining end shown. The webs of paper may be described as essentially saturated with moisture. To obtain a proper and secure bond between the several layers of paper it is necessary that the glue set. This requires heat not only for the purpose of setting the glue but also for the purpose, at least to some extent, of drying the paper prior to scoring and trimming it to size. The major purpose of the preheating drums V119 and preheating drum 29 is to condition the paper and cause heat transfer through the paper to enable the proper application of the glue to the corrugations and secure an initial set of the glue.

A further problem encountered in making triple wall paper board is that a heating or drying section which has been generally indicated by the numeral 37 in the drawings, which will supply heat to both sides of the composite sheet is difficult and complicated to build.

When heat is applied to only one side of the composite sheet as in making triple wall corrugated paper board, by the more conventional machine shown by the drawings,

the heat must penetrate five layers of paper before it reaches the corrugations '11. It is therefore diflicult to obtain proper setting of the glue and an adequate bond between the uppermost ply of. corrugated paper board and the intermediate plies of corrugated paper board.

In FIG. 1, by breaking off the heating or drying sec tion 37, the inventors have distorted the drawing. However, it will be understood that the heating and drying section is relatively long. In the machine with which they originally produced triple wall corrugated paper board, the heating and drying section was approximately 43 feet long. i1" heyv found that the various layers of paper board may be bonded together to secure a rigid board structure if the heatingsection is relatively long and the speed of the composite sheet and the temperature of the hot plates are maintained within certain well defined limits. A good bond can then be obtained without scorching or burning the sheet. They carried out a large num ber of experiments to determine the proper speed-temperature relationship and found that by accurately controlling the temperature and speed of movement of the composite corrugated paper board through the heating or drying section, good quality triple wall corrugated paper board may :be obtained in a continuous and commercially practicable manner.

The heater section 37 comprises a long series of hot plates which have been diagrammatically illustrated at 38. These hot plates are supplied with steam by means not shown. The upper face of the lower run of the belt 33 may be somewhat weighted down by rollers 39 vtoapply some pressure between the belt and the hot plates to secure better heat transfer.

The inventors found that the temperature of the hot plates should be between 300 and 330 F. Below 300 F. the paper board is not adequately dried and the glue does not set properly, and above 330 F. the paper, particularly the lower liner sheet, becomes scorched. However, preferably the temperature of the hot plates should be between 325 and 330 F. Within these temperature limits, the inventors found that the speed of travel of the composite sheet cannot be less thanl' per-minuteand cannot be in excess of 175' per minute, to obtain the good quality previously referred to. Below the lower limit of this speed the paper tends toscorch and beyond the upper limit of this speed adequate drying and setting of the adhesive is not secured. However, far better results are secured if the speed of travel is maintained between and per minute. If the temperature of the hot plate is maintained, say at 300 F, then the speed of travel of the composite sheet should be relatively slow, approximately 100' per minute. If the temperature of the hot plates is raised to 350 F., the speed of travel of the composite sheet may be increased to as much as per minute but is preferably about 135 to 150' per minute. The above limits are being considered in connection with a heating and drying section approximately 40' long.

An exact temperature-speed relationship cannot be set forth because of the variables encountered. The temperature-speed relationship will vary with the humidity, the thickness of the paper, its porosity and other factors which may vary from hour to hour. These factors were common knowledge when this invention was made. They included the roll change, slow downs of necessity, the kind of glue used and the like, as is well-known in this art. However, it is newssary to control the temperature-speed relationship approximately within the limits above set forth, to obtain the good quality referred to in connection with the temperature-time values described.

The machine is adapted to produce A, B and C flutes for which standards have been set up by the corrugated box industry. In FIG. 4, the inventors show a composite board made of an A flute which is the central ply, a B flute which is the uppermost ply, and a C flute which is the lowermost ply. Experiments have shown that the arrangement of the flutes affects the strength characteristics of the board produced although this constitutes no part of our present invention. It is suflicient to state that the machine of our invention is capable of producing A, B and C flutes in any desired combination.

After the composite corrugated paper board has passed through the drying section, it passes to a cooling and drying section and thence to a duplex scoring machine, the construction of which is well known in the art. The cooling section lies between the end of the hot plates and the duplex scoring machine. It comprises a pair of pulleys one of which is driven, over which a belt 36 passes. The upper run of the belt passes over cooling plates 40 which may be the same as the hot plates 38 but to which no steam is supplied. The belt 33 passes over both the heating section and the cooling section. In the cooling section the glue sets to secure proper adhesion of the sheets prior to the scoring and cut off operations.

In general, as shown in FIG. 5 the scoring machine comprises a pair of shafts 41 which may be driven in any suitable manner (not shown). The shafts 41 are mounted in suitable side plates 42 mounted on a shaft 43. The shaft is rotatably supported in and by means'of a suitable frame 44. In a duplex scorer, two sets of scoring rolls are mounted in the end plates 42 so that one set of scoring devices 47 may be employed while a second set of scoring devices 48 may be set up for the next run of board to be placed .on the machine. When the next run is started, the shaft 44 is rotated through F. to

bringthe scoring devices 48 in the uppermost position.

One of the problems encountered in connection with the making of triple wall corrugated paper board lies in securing a proper scoring areaor strip lengthwise of the web as it travels through the machine and transverse to the direction of the corrugations which will enable the bending of the board along the score area without breaking or tearing the board. In single ply or wall double face paper board a line of scoring is adequate to enable the folding of the sections on opposite sides of the score line at right angles to each other. However, triple Wall corrugated paper board is relatively thick and at least three lines of scoring must be produced in the paper board which may "be termed an area or strip of scoringv as distinguished from a line of scoring. This strip scoring is produced by having a scoring strip or area in the male die as well as in the female die.

As :an example, in the making of triple wall corrugated paper board having A, B and C flutes such as shown in FIG. 4, the total thickness of the composite sheet is theoretically This particular board has liner thicknesses of .016" and corrugating medium thicknesses of .009". In corrugated paper board, an A flute is .181 high, a B flute .103" and a C flute .145" high. Because the corrugating rolls may be worn and the composite sheet is somewhat flattened upon being passed through the drying section, the total thickness of the composite sheet may vary between /8 and /2". Of course if all A flutes were employed, the total thickness of the composite sheet would be greater.

To enable a board of such thickness to be scored properly for bending of the sections on opposite sides of the score line at right angles to each other, an area or strip of scoring must be provided to avoid breaking or tearing the liner on the external side of the bend and also to avoid completely collapsing the liner and its adjacent corrugations on the inside of the bend.

In FIG. 6 a male die 51 and a female die 52 are mounted on the shafts 41. The male die has a continuous ring or projection 53 rectangular in cross section. The female die has a depression 54 also rectangular in cross section. It has been found to be desirable .to make the width of the female die at least not, materially less than die and in the particular illustration shown this width is' 7 to allow for side clearance. This side clearance, indicated at 55, is approximately .045. The amount of penetration of the male die into the female die is preferably somewhat larger than the amount of side clearance.

The amount of side clearance may be made as much as as of the thickness of the paper board but cannot be decreased to less than of the thickness of the composite board. With these ratios of side clearance to board thickness; with the amount of penetration somewhat larger than the side clearance; and with the width of the female die at least not materially less than the thickness of the board, a clean breaking of the board may be obtained without, almost invariably, breaking the outer liner or completely collapsing the corrugations.

A further problem encountered in making a score line for triple wall corrugated paper board lies in the fact that it is necessary to produce an area or strip of scoring as distinguished from a line of scoring. This fact may result, when the board is bent at right angles about the strip of scoring, in the material bending diagonally across the scoring strip. By forming a slight projection 56 in the center of the projection 53 of the male .die, a line of bending is induced in the composite sheet so that in bending the paper board, the bending almost invariably occurs along a line of bend in alignment with the annular projection 56. It will be particularly noted as indicated at 57 that all corners of both the female and male dies are provided with radii to avoid tearing the material and that the dies shown produce at least three lines of scoring located along a strip.

A strip of scoring produced by male and female dies in approximately the proportions described above and provided with a projection such as 56 to induce a line of bend, enables the board to be bent along the longitudinal strip of scoring almost invariably without breaking the outer liner and with the line of bend in a straight line in alignment with the projecting annular section 56.

While the present inventors have shown and described the preferred form of their invention, it will be apparent that various changes and modifications may be made therein, particularly in the form and relation of par-ts, without departing from the spirit of their invention as set forth in the appended claims.

What is claimed is:

1. Triple wall corrugated paper board which is flat and adapted for scoring and bending to form a shipping container and consisting essentially of four paper liners, three corrugated paper mediums, the mediums being individually interposed between two liners in each instance, and adhesive applied to the ridges of the mediums corrugations and the liners and intimately and rigidly bonding the mediums and liners together, the corrugations of the mediums being parallel to each other throughout said board and high enough so that the total thickness of said board is at least and the total thickness of the liners and mediums being at least approximately .091", this total thickness being distributed between the liners and mediums so that said board is strong and rigid, said triple wall corrugated paper board having been made by a single pass of all of said sheets prior to setting of said adhesive simultaneously through a corrugated paper board machine having a heating and drying section operated at a temperature within the range of approximately 300 to approximately 350 F. and at a temperature-speed relationship which is varied with the humidity, the thickness, and porosity of said sheets to provide a residence time in said section sufiicient to set said adhesive and make a rigid and strong triple wall corrugated paper board.

2. Triple wall corrugated paper board which is fiat and adapted for scoring and bending to form a shipping container and consisting essentially of four paper liners, three corrugated paper mediums, the mediums being individually interposed between two liners in each instance, and adhesive applied to the ridges of the mediums corrugations and the liners and intimately and rigidly bonding the mediums and liners together, the corrugations of the mediums being parallel to each other throughout said board and high enough so that the total thickness of said board is at least /2", and the total thickness of the liners and mediums being at least approximately .091", this total thickness being distributed between the liners and mediums so that said board is strong and rigid, said triple wall corrugated paper board having been made by a single pass of all of said sheets prior to setting of said adhesive simultaneously through a corrugated paper board machine having a heating and drying section operated at a temperature within the range of approximately 300 to approximately 350 F. and at a temperature-speed relationship which is varied with the humidity, the thickness, and porosity of said sheets to provide a residence time in said section sufficient to set said adhesive and make a rigid and strong triple wall corrugated paper board, the corrugations of at least one of the mediums being at least approximately .181" high.

3. Triple wall corrugated paper board which is fiat and adapted for scoring and bending to form a shipping container and consisting essentially of four paper liners, three corrugated paper mediums, the mediums being indi vidually interposed between two liners in each instance, and adhesive applied to the ridges of the mediums corrugations and the liners and intimately and rigidly bonding the mediums and liners together, the corrugations of the mediums being parallel to each other throughout said board and high enough so that the total thickness of said board is at least /2", and the total thickness of the liners and mediums being at least approximately .091", this total thickness being distributed between the liners and mediums so that said board is strong and rigid, said triple wall corrugated paper board having been made by a single pass of all of said sheets prior to setting of said adhesive simultaneously through a corrugated paper board machine having a heating and drying section operated at a temperature within the range of approximately 300 to approximately 350 F. and at a temperature-speed relationship which is varied with the humidity, the thickness, and porosity of said sheets to provide a residence time in said section suhicient to set said adhesive and make a rigid and strong triple wall corrugated paper board, the corrugations of at least one of the mediums being at least approximately .181" high, at least the liners on the outsides of said board being thicker than the thickest one of the mediums.

References Cited in the file of this patent UNITED STATES PATENTS 1,196,956 Kelleher Sept. 5, 1916 1,361,564 'Callery Dec. 7, 1920 1,839,200 Clarke Ian; 5, 1932 2,018,800 Morton Oct. 29, 1935 2,160,221 Masters et a1 May 30, 1939 2,289,909 Greenwood July 14, 1942 2,475,789 Kunz July 12, 1949 

3. TRIPLE WALL CORRUGATED PAPER BOARD WHICH IS FLAT AND ADAPTED FOR SCORING AND BENDING TO FORM A SHIPPING CONTAINER AND CONSISTING ESSENTIALLY OF FOUR PAPER LINERS, THREE CORRUGATED PAPER MEDIUMS, THE MEDIUMS BEING INDIVIDUALLY INTERPOSED BETWEEN TWO LINERS IN EACH INSTANCE, AND ADHESIVE APPLIED TO THE RIDGES OF THE MEDIUMS'' CORRUGATIONS AND THE LINERS AND INTIMATELY AND RIGIDLY BONDING THE MEDIUMS AND LINERS TOGETHER, THE CORRUGATIONS OF THE MEDIUMS BEING PARALLEL TO EACH OTHER THROUGHOUT SAID BOARD AND HIGH ENGOUGHSO THAT THE TOTAL THICKNESS OF SAID BOARD IS AT LEAST 1/2", AND THE TOTAL THICKNESS OF THE LINERS AND MEDIUMS BEING AT LEAST APPROXIMATELY .091", THIS TOTAL THICKNESS BEING DISTRIBUTED BETWEEN THE LINERS AND MEDIUMS SO THAT SAID BOARD IS STRONG AND RIGID, SAID TRIPLE WALL CORRUGATED PAPER BOARD HAVING BEEN MADE BY A SINGLE PASS OF ALL OF SAID SHEETS PRIOR TO SETTING OF SAID ADHESIVE SIMULTANEOUSLY THROUGH A CORRUGATED PAPER BOARD MACHINE HAVING A HEATING AND DRYING SECTION OPERATED AT A TEMPERATURE WITHIN THE RANGE OF APPROXIMATELY 300* TO APPROXIMTELY 350*F. AND AT A TEMPERATURE-SPEED RELATIONSHIP WHICH IS VARIED WITH THE HUMIDITY, THE THICKNESS AND POROSITY OF SAID SHEETS TO PROVIDE A RESIDENCE TIME IN SAID SECTION SUFFICIENT TO SET SAID ADHESIVE AND MAKE A RIGID AND STRONG TRIPLE WALL CORRUGATED PAPER BOARD, THE CORRUGATIONS OF AT LEAST ONE OF THE MEDIUMS BEING AT LEAST APPROXIMATELY .181'''' HIGH, AT LEAST THE LINERS ON THE OUTSIDES OF SAID BOARD BEING THICKER THAN THE THICKEST ONE OF THE MEDIUMS. 